S.L. Boyles*, H.M. Bartholomew+, and R.M. Sulc++
*Department of Animal Sciences
+The Ohio State University Extension
++Department of Horticulture and Crop Science
Livestock producers actively participated in a demonstration project to extend the grazing season and to evaluate dormant forage quality and yield. Differences were not detected in yields among forage species, but yield differences existed among sites. Yield estimates did not change over time across all forage species, but some sites only were able to participate for two months. Producers utilizing fescue beyond November had reductions in herbage mass. Crude protein, available crude protein, acid detergent fiber, and neutral detergent fiber content differed among forage species and sites. However, energy and lignin content were similar for all forage species and sites. Sodium and copper were perhaps the most universally deficient minerals. While magnesium levels appeared adequate, the relatively high potassium levels could interfere with magnesium absorption. Mean fescue endophyte content was 67%, which could prevent maximum animal performance. Based on this project and other information, a beef cattle grazing manual was printed, and two thousand copies have been distributed.
Pasture represents a largely untapped resource for Ohio agriculture. Of the 16 million acres of Ohio farmland, over 2.5 million acres are in some form of pasture (Sulc, 1992). The profitability of livestock operations is largely determined by feed cost. The most expensive feed cost for Ohio cow-calf producers continues to be hay production (Fowler and Stout, 1990; White, 1969). This is also the case in other parts of the north central region. (Hughes, 1990; Strohbehn, 1992).
Developing winter grazing systems could effectively reduce or eliminate the cost of hay production. This would reduce the requirement for purchased inputs such as fuel and equipment. Labor for the winter period can be reduced to 25% of that of conventional wintering of beef cows in Ohio (Van Keuren, 1970). Small- and medium- size cattle operations have fewer production units (cows) to spread fixed costs. Improving the profitability of beef cattle operations should assist in sustaining Ohio rural communities. The objectives of this project were 1) to involve Ohio beef and sheep producers in a profit oriented extension/research project and 2) to characterize dormant forage resources of Ohio.
| Table 1. Participants in sustainable winter grazing project. | ||||
| County | Extension Agent | Producer | Site | Specie |
| Athens | Henry Bartholomew | Rick Duff | 1 | Sheep |
| Richard Jeffers | 2 | Beef Cows | ||
| Belmont | Stephen Schumacher | Denver Keiser | 3 | Sheep |
| Carroll | Mike Hogan | Earl McKarns | 4 | Beef Cows |
| Gallia | Ed Vollborn | Bob Evans | 5 | Beef Cows |
| Highland | Troy Putnam | Dave Perry | 6 | Beef Cows |
| Hocking | Henry Bartholomew | Jim Rodgers | 7 | Beef Cows |
| Jackson | David Samples | Dean Armstrong | 8 | Beef Cows |
| Milt Call | 9 | Beef Cows | ||
| Knox | Mark Bennett | Mark Smith | 10 | Beef Cows |
| Dale Black | 11 | Beef Cows | ||
| Greg Miller | 12 | Beef Cows | ||
A total of 12 producers participated in the winter grazing project (Table 1). Sites were allowed to participate if they had 1) enough standing regrowth to furnish forage dry matter (DM) requirements for cows or sheep for thewinter grazing period, 2) sufficient protection for animals from prevailing winds, 3) adequate soil drainage, and 4) a constant supply of water. Animals needed to have adequate body condition to maintain themselves during the winter.
Herbage Mass. Determinations of herbage mass were made the first day that animals had access to a new plot area (Mowery et al., 1992). A 3/8 inch steel rod was used to make a square. This device is called a quadrat, and the area of the quadrat was 2 square feet. Forage mass was measured by hand-clipping (Milner and Hughes, 1968). Three samples were taken per pasture to be grazed. Standing herbage was clipped to about 1 inch of the soil surface (Bosworth, 1988). Forage and hay samples were dried at 55oC for 48 hours and then ground to pass a 1 mm screen. The dry sample weights were converted to pounds of herbage per acre (1 acre = 43,560 ft2). Pounds of DM per acre were then determined. The yield of DM was used to calculate how many grazing days were possible. In this demonstration project, only the pasture that was to be used immediately was sampled. If the animals remained on the same pasture for an extended amount of time, the pasture was resampled every 30 days.
Forage Quality. Pastures to be used were sampled every 30 days. This was done to observe how pasture quality changes over time. Hand-cut samples (40 mm stubble) for quality estimates were taken along the quadrat area. Three samples per pasture were taken and mixed together and then subsampled. The subsample was sent to the laboratory for forage quality analysis. Quality factors were DM, energy, protein, fiber, and mineral contents. Soil samples also were collected at each site. Selected fescue samples were collected to measure endophyte content of the pasture.
Animal Performance. Producers observed the animals' body condition. It became impractical to weigh animals due to limitations on farm labor and lack of scales. However, no significant health problems were reported. Hay was allotted to animals during the particularly harsh winter conditions.
| Table 2. Forage type used at each grazing site by month.1 | ||||
| Oct. | Nov. | Dec. | Jan. | |
| Site 1 | RC,OG | OG,FE,RC | OG,BG | . . . |
| Site 2 | FE | FE | FE | FE |
| Site 3 | FE | BG,OG | OG | . . . |
| Site 4 | RC,OG | RC,OG | . . . | . . . |
| Site 5 | FE | FE | FE | FE |
| Site 6 | FE | FE | . . . | . . . |
| Site 7 | FE | OG/FE | . . . | . . . |
| Site 8 | FE | FE | FE | FE |
| Site 9 | FE,RC | FE,RC | . . . | . . . |
| Site 10 | BG | OG/OG,BG | . . . | . . . |
| Site 11 | FE,RC,Al | FE,RC,Alf | . . . | . . . |
| Site 12 | OG | OG | . . . | . . . |
| 1 RE = fescue, RC = red clover, Alf = Alfalfa, OG = orchardgrass, BG = bluegrass, Pasture switch within month = /. | ||||
All pastures at each farm site were classified with regard to plant species. In Table 2, the predominant species is listed first, and lesser species are listed in descending order. For example, red clover-fescue mixture that is predominantly red clover is listed as RC,FE. Fescue was the major forage species in this study, representing 48.5% of the forage samples and followed by red clover-orchardgrass at 12.1% of the samples. The rest of the forage samples were represented by orchardgrass (9.1%), orchardgrass-bluegrass (9.1%), fescue-red clover-alfalfa (6.1%), fescue-red clover (6.1%), fescue-red clover-orchardgrass (3.0%), fescue-orchardgrass (3.0%), and bluegrass (3.0%).
All producers were able to extend their grazing season. Fescue is usually recommended if extending the grazing season further into the winter is desired. Site 4 was able to use an orchardgrass-bluegrass mixture (OG,BG) into December, but the previous November pasture contained some fescue. The particularly harsh winter precluded further use of the pastures for most producers. Orchardgrass and bluegrass were effectively used by other producers during October and November.
Herbage Mass. Table 3 lists the DM yields from pastures at the various sites by month. Differences were not detected in yields between forage species within months during October (P = 0.67), November (P = 0.37), and December (P = 0.94). This should not be interpreted that producers can use state-wide averages to determine local forage yields. Site variation in forage yield within month did exist (P < 0.05).
Multiple regression analyses was not able to detect (P = 0.25) change in forage yield over time when all forage species were evaluated. However, many forage species only were used in October and November. Harsh weather usually is more prevalent during December and January. A loss of DM occurred when fescue alone was evaluated over the inclusive period of October through January (P = 0.10). DM yields were greatest for urea-fertilized fescue pastures. Sites 2 and 3 did not utilize urea on their fescue. Fescue pasture yields effectively were doubled by the use of urea fertilization. However, DM yield decreased by 1000 pounds/acre from December to January. This effectively reduced the stocking rate by one cow from December to January (Table 4). Producers need to take into account this DM loss due to weathering when planning to extend the grazing season beyond early December.
| Table 3. Herbage mass based on location, forage type, and date. | ||||
| Dry matter, pounds per acre | ||||
| Specie/Location | October | November | December | January |
| Fescue | ||||
| Site 2 | 992+ 540.0 | 920+ 417.3 | 876+163.4 | 552+186.9 |
| Site 2 | . . . | . . . | . . . | 760+372.8 |
| Site 3 | 912+487.1 | . . . | . . . | . . . |
| Site 5 | 3607+1327.0 | 4382+1555.2 | 4367+1338.0 | 2791+540.0 |
| Site 6 | 1600+ 517.7 | 1112+ 361.1 | . . . | . . . |
| Site 7 | 1568+ 293.3 | . . . | . . . | . . . |
| Site 8 | 2088+ 500.6 | 2511+ 413.8 | 3039+341.4 | 2335+154.3 |
| Fescue, Red | ||||
| Site 9 | 1400+ 176.9 | 1943+ 495.4 | . . . | . . . |
| Fescue, Red Clover, Alfalfa | ||||
| Site 11 | 1647+ 499.0 | 1776+213.3 | . . . | . . . |
| Bluegrass | ||||
| Site 10 | 2415+ 492.7 | . . . | . . . | . . . |
| Site 10 | 2207+ 166.3 | . . . | . . . | . . . |
| Bluegrass, Orchardgrass | ||||
| Site 3 | . . . | 1408+ 390.2 | . . . | . . . |
| Red Clover, Orchardgrass | ||||
| Site 1 | 696+ 145.9 | . . . | . . . | . . . |
| Site 4 | 1040+ 556.3 | 1815+ 561.9 | . . . | . . . |
| Orchardgrass | ||||
| Site 3 | . . . | 2295+ 766.3 | . . . | . . . |
| Site 10 | . . . | 2183+ 345.7 | . . . | . . . |
| Site 10 | . . . | 1816+ 186.4 | . . . | . . . |
| Site 12 | 1104+ 120.0 | 1816+ 239.9 | . . . | . . . |
| Orchardgrass, Fescue | ||||
| Site 7 | . . . | 1652+ 353.5 | . . . | . . . |
| Orchardgrass, Fescue, Red | ||||
| Site 1 | . . . | 1560+ 413.8 | . . . | . . . |
| Orchardgrass, Bluegrass | ||||
| Site 1 | . . . | . . . | 664+ 363.5 | . . . |
| Site 10 | . . . | 1344+ 444.5 | . . . | . . . |
| Site 10 | . . . | 912+ 267.3 | ||
| Table 4. Stocking rate per acre per month for beef cows, assuming dry matter consumption of 30 pounds of dry matter per day required. | ||||
| Beef cows per acre per month | ||||
| Specie/Location | October | November | December | January |
| Fescue | ||||
| Site 2 | 1.10+0.600 | 1.02+0.464 | 0.97+0.82 | 0.61+0.207 |
| Site 2 | . . . | . . . | . . . | 0.84+0.144 |
| Site 3 | 1.01+0.541 | . . . | . . . | . . . |
| Site 5 | 4.01+1.474 | 4.86+1.728 | 4.85+1.487 | 3.10+0.600 |
| Site 6 | 1.78+0.575 | 1.24+0.401 | . . . | . . . |
| Site 7 | 1.74+0.326 | . . . | . . . | . . . |
| Site 8 | 2.32+0.556 | 2.79+0.460 | 3.38+0.379 | 2.59+0.171 |
| Fescue, Red | ||||
| Site 9 | 1.56+0.196 | 2.15+0.550 | . . . | . . . |
| Fescue, Red Clover, Alfalfa | ||||
| Site 11 | 1.83+0.554 | 1.97+0.237 | . . . | . . . |
| Bluegrass | ||||
| Site 10 | 2.68+0.547 | . . . | . . . | . . . |
| Site 10 | 2.45+0.185 | . . . | . . . | . . . |
| Bluegrass, Orchardgrass | ||||
| Site 3 | . . . | 1.56+0.434 | . . . | . . . |
| Red Clover, Orchardgrass | ||||
| Site 1 | 0.77+0.162 | . . . | . . . | . . . |
| Site 4 | 1.16+0.618 | 2.02+0.624 | . . . | . . . |
| Orchardgrass | ||||
| Site 3 | . . . | 2.55+0.851 | . . . | . . . |
| Site 10 | . . . | 2.43+0.384 | . . . | . . . |
| Site 10 | . . . | 2.02+0.207 | . . . | . . . |
| Site 12 | 1.23+0.133 | 2.02+0.266 | . . . | . . . |
| Orchardgrass, Fescue | ||||
| Site 7 | . . . | 1.84+0.393 | . . . | . . . |
| Orchardgrass, Fescue, Red | ||||
| Site 1 | . . . | 1.73+1.733 | . . . | . . . |
| Orchardgrass, Bluegrass | ||||
| Site 1 | . . . | . . . | 0.74+0.404 | . . . |
| Site 10 | . . . | 1.49+0.494 | . . . | . . . |
| Site 10 | . . . | 1.01+0.297 | . . . | . . . |
It should not be concluded that nonprotein nitrogen fertilization is an absolute requirement for extending the grazing season. Additional acreage may be considered foroperations that are currently under-stocked. Fescue pastures that contained a legume at least approached the DM yields of urea fertilized fescue pastures.
Forage Quality (Protein, Energy, and Fiber). Table 5 contains the forage specie protein, energy, and fiber values for the winter grazing project. Average forage crude protein content was 14.4% but ranged from 8.5 to 23.5%. Crude protein, available crude protein, acid detergent fiber, and neutral detergent fiber differed among forage species and sites (P < 0.06). However, energy and lignin contents were similar for all forage species and sites (P > 0.20).
Forage Quality (Minerals). Table 6 contains selected mineral contents and levels of significance for different forage species. The average phosphorus content was 0.24%, which is adequate to borderline for dry, pregnant spring- calving cows (NRC, 1984). However, several forage species had values lower than the suggested requirements, and the lower range for phosphorus content was 0.12%. The mean calcium content was 0.53% and ranged from 0.26% to 0.92%. The average copper content was 4 ppm, which is well below the suggested minimum level of 10 ppm (NRC, 1996). The highest level of copper reported among the forage samples was 10 ppm. Average zinc levels were 27 ppm (range 12 to 52 ppm), which was less than the 30 ppm suggested minimum. Magnesium levels appeared to be adequate, but the relatively high level of potassium present (1.72%) may interfere with magnesium absorption. Sodium levels were uniformly low in all samples (range 1 to 428 ppm). Iron levels were typically above the suggested NRC minimum of 50 ppm, but the lower range for forage samples was 36 ppm. Typical manganese levels were 86 ppm, but a few samples had levels below the 40 ppm suggested minimum.
Soil Tests. Soil tests were performed on the pastures included in the project. The soil test level at which the soil can supply adequate quantities of a particular nutrient for plant growth is called the "critical" level for that nutrient. For grass pastures, the critical soil test levels are as follows: pH = 6.0; phosphorus = 30 pounds/acre; and potassium = 150 pounds/acre (5 x cation exchange capacity). If tall-growing legumes are present, the critical pH is 6.5 or higher (except for annual lespedeza), and phosphorus is 50 pounds/acre. Of the pastures in this project, 5 tested below the critical pH level, 9 were below the critical phosphorus level, and 5 were below the critical potassium level for grass pastures. Corrective applications of lime and fertilizer on these deficient sites would improve forage production potential, especially where a legume component is to be maintained.
Animal Performance. In general, the participating producers felt that animal performance was adequate. Two producers reported that animal performance prior to the beginning of the trial was less than acceptable. Based on reported animal symptoms and forage analyses, copper levels were determined to be deficient. Mean endophyte content of the fescue was 67%, with a range of 23% to 100%. The estimated reduced gain would be 1.4 to 1.6 pounds/day.
| Table 5. Forage protein, energy, and fiber values for winter grazing. Demonstration project (100% dry matter basis).1 | ||||||||
| Species | CP2 | ACP | NEL | NEm | NEg | ADF | Lig | NDF |
| (%) | (Mcal/pound) | (%) | ||||||
| Fescue | 13.2 | 12.7 | 0.60 | 0.59 | 0.29 | 36.9 | 5.0 | 60.4 |
| Fes-RC-A | 10.7 | 10.2 | 0.57 | 0.56 | 0.23 | 37.7 | 7.0 | 63.0 |
| Fes-RC-OG | 12.1 | 10.4 | 0.58 | 0.56 | 0.25 | 38.2 | 5.0 | 63.3 |
| Fes-OG | 18.9 | 18.9 | 0.56 | 0.54 | 0.22 | 22.1 | 9.0 | 45.1 |
| RC-Fes | 18.5 | 18.5 | 0.66 | 0.66 | 0.37 | 25.8 | 4.0 | 46.3 |
| RC-OG | 19.1 | 18.9 | 0.64 | 0.63 | 0.34 | 27.9 | 5.0 | 48.2 |
| OG-BG | 13.3 | 12.0 | 0.63 | 0.61 | 0.31 | 35.6 | 3.0 | 59.9 |
| BG | 13.6 | 12.4 | 0.66 | 0.66 | 0.37 | 35.4 | 3.0 | 60.0 |
| OG | 14.4 | 13.3 | 0.58 | 0.57 | 0.25 | 37.1 | 6.0 | 60.2 |
| Std. dev.3 | 3.22 | 3.51 | 0.045 | 0.050 | 0.072 | 5.38 | 2.2 | 7.03 |
| P4 | 0.04 | 0.05 | 0.24 | 0.28 | 0.38 | 0.03 | 0.33 | 0.04 |
| 1 Fes = Fescue, RC = Red clover, A = Alfalfa, OG = Orchardgrass, BG = Bluegrass.
2 CP = crude protein, ACP = available crude protein, NEL = net energy lactation, NEm = net energy maintenance, NEg = net energy gain, ADF = acid detergent fiber, Lig = lignin, NDF = neutral detergent fiber. 3 Standard deviation of least square mean. 4 Probability level. | ||||||||
| Table 6. Forage mineral values for winter grazing demonstration project.1 | ||||||||||
| Specie | Ca2 | P | K | Mg | S | Mn | Fe | Cu | Zn | Na |
| (%) | (ppm) | |||||||||
| Fescue | 0.47 | 0.24 | 1.6 | 0.22 | 0.2 | 66 | 117 | 3 | 22 | 38 |
| Fes-RC-A | 0.62 | 0.18 | 1.4 | 0.29 | 0.2 | 57 | 106 | 4 | 20 | 58 |
| Fes-RC-OG | 0.54 | 0.18 | 1.6 | 0.24 | 0.2 | 83 | 74 | 3 | 22 | 24 |
| Fes-OG | 0.29 | 0.26 | 2.4 | 0.19 | 0.2 | 147 | 73 | 5 | 29 | 15 |
| RC-Fes | 0.44 | 0.28 | 2.2 | 0.33 | 0.2 | 86 | 55 | 4 | 23 | 21 |
| RC-OG | 0.77 | 0.30 | 2.3 | 0.28 | 0.2 | 102 | 170 | 8 | 42 | 230 |
| OG-BG | 0.54 | 0.19 | 1.4 | 0.21 | 0.2 | 122 | 385 | 6 | 32 | 87 |
| BG | 0.48 | 0.24 | 1.7 | 0.22 | 0.2 | 184 | 101 | 6 | 29 | 9 |
| OG | 0.60 | 0.22 | 1.4 | 0.18 | 0.2 | 104 | 198 | 5 | 33 | 4 |
| Std. Dev.3 | 0.163 | 0.064 | 0.45 | 0.073 | . . . | 6.9 | 119 | 1.7 | 9.2 | 76.6 |
| P4 | 0.11 | 0.44 | 0.09 | 0.36 | . . . | 0.04 | 0.09 | 0.01 | 0.05 | 0.02 |
| 1 Fes = Fescue, RC = Red clover, A = Alfalfa, OG = Orchardgrass, BG = Bluegrass.
2 Ca = calcium, P = phosphorus, K = potassium, Mg = magnesium, S = sulfur, Mn = manganese, Fe = iron, Cu = copper, Zn = zinc, Na = sodium. 3 Standard deviation of least square means. 4 Probability level. | ||||||||||
Bosworth, S.C. 1988. Methods of measuring pasture yields. In:Pasture in the Northeast Region of the United States. Northeast Regional Agricultural Engineering Service. p. 105.
Fowler, K.F., and T.T. Stout. 1990. Cow-calf profitability in southeast Ohio: Twenty-five 1987 cases. Ohio Beef Cattle Res. Ind. Rep., The Ohio State University. p. 86.
Hughes, H.H. 1990. The economic reality of your beef cow herd. Farm Mang. Plan. Guide, North Dakota State University. Sect 5. No. 22.
Milner, C., and R.E. Hughes. 1968. Methods of the measurement of primary production of grassland. Blackwell Sci. Publ., Oxford, England.
Mowery, D.P., A.G. Matchers, and R.L. Preston. 1992. Technical Note: Utilization of saifoin by grazing steers and a method for predicting daily gain from small-plot grazing data. J. Anim. Sci. 70:2262.
NRC. 1996. Nutrient Requirements of Beef Cattle 7th ed. National Academy Press. Washington, D C.
NRC. 1984. Nutrient Requirements of Beef Cattle 6th Ed. National Academy Press. Washington, D C.
Strohbehn, D.R. 1992. A nine-year summary of the ISU beef cow business records. Beef-Sheep Res. Rep., Iowa State Univ. p. 90.
Sulc, R.M. 1992. Managing forages to improve pasture productivity. OVMA Convention. pp. 199.
Van Keuren, R.W. 1970. All-season grazing for beef cow. Research Summary No. 43. Ohio Agri. Res. Dev. Center. p. 1.
White, B.L. 1969. An economic comparison of beef cow-calf feeding systems in southern Ohio. Thesis. The Ohio State University, Columbus.